Toyota Prius Forums banner
1 - 2 of 2 Posts

1 Posts
Discussion Starter · #1 ·
Hello Prius fam,

I have an '07 that has had some strange electrical issues (I'm assuming electrical) for several years, only now the problem seems to be getting worse.

On the dash the ABS, VSC, (!), and Red Triangle light have been lit for years. The only immediate problems: the cruise control doesn't work, nor does the anti-lock system. I was able to drive fine in this situation, so I ignored it.

Recently, all packed up during a hot summer day, a strange beep sounded in the car and it shifted (without me doing anything) from Drive into Neutral. (The AC also went out) It caused me to pull over and restart the car. This repeated three times before I let the car cool down, then I was able to drive it all the way home, driving slowly on backroads.

After checking out the car, the only thing the dealer could come up with was that I needed a new 12v battery -- and there was a chance it could solve everything. So I put one in and all the lights (and Check Engine) are still lit up! The car hasn't shifted into Neutral while driving, but the AC went out briefly today, and the car was hulking while I was doing 65 on the highway -- it also seemed to be struggling to get into gear, like there's an issue with the "transmission." (It's worth mentioning that this was after I'd driven a good 20 miles on the highway, and it was a hot day.)

I know there could be several issues going on, but I'd like to think there's some simple problem in the electrical system that's trigging all this madness.

Any help would be greatly appreciated, as the dealers (I've been diagnosed by two so far!) can't seem to figure it out.


Super Moderator
'17 C 4
663 Posts
Welcome to the forum.

The "old" problem that you have causing the lights to be on probably is a fault in the ABS brake system......which leaves you with normal non-ABS brakes.....hopefully.

That likely has nothing to do with your new problems.

Maybe you should get the brakes fixed first and then see what fault codes are left.

If the shops understand that there are (at least) two separate and distinct problems, they might be better able to recommend a course of action.

I agree with changing the 12 V battery first.
It might be a good idea to fully charge it with a manual charger just to be sure........but highly unlikely that will make any difference in the problems that you are having.

P.S. If you have high mileage on this 10 year old car, it might not be worth fixing. Some of the symptoms you report might be due to a failing HV hybrid battery.
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.